Sheet Feeding Device Regulating Member Gap Design
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Solution Overview
Problem
Conventional air suction sheet feeding devices fail to prevent double feeds when conveying thick paper, as the pawl-like member rotates due to the thickness of the paper, leading to improper sheet separation.
Innovation Solution
A sheet feeding device with a suction conveyor and a blower that includes horizontal portions and a recess, along with a regulating member positioned downstream to ensure that the gap between the regulating member and the horizontal portions is less than twice the thickness of the paper, preventing double feeds by regulating the movement of subsequent sheets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pawl-like member is used to prevent double feeds, then double feed prevention is improved for thin paper, but the pawl-like member rotates due to thick paper abutting against it, causing double feed prevention to fail
Solution Approach 1:
The patent removes the pawl-like member from the sheet feeding mechanism and replaces it with a regulating member that defines a gap structure. This extraction eliminates the rotation problem caused by thick paper while maintaining double feed prevention functionality through the carefully controlled gap between the regulating member and suction conveyor.
Solution Approach 2:
The patent changes the critical parameter from the pawl-like member's rotational mechanics to the gap dimension between the regulating member and suction conveyor. By controlling the gap to be less than twice the sheet thickness, the system reliably prevents double feeds for various paper thicknesses without mechanical rotation issues.
2Ease of manufacture
If the gap between the regulating member and horizontal portions is made larger, then ease of manufacture is improved, but double feed prevention reliability deteriorates
Solution Approach 1:
The patent establishes a specific parameter relationship where the gap is set to less than twice the sheet thickness. This parameter setting achieves an optimal balance: it is large enough to allow single sheet passage and manufacturing tolerance but small enough to prevent simultaneous passage of multiple sheets, thereby maintaining reliability.
3Reliability
If the projection height of the regulating member is increased, then double feed prevention is improved, but the risk of catching sheets increases
Solution Approach 1:
The patent applies local quality by creating a specific gap structure at the critical location between the regulating member and suction conveyor. The regulating member's projection height is optimized to create a localized control zone that prevents double feeds without excessively protruding into the sheet path, thus avoiding sheet catching while maintaining separation effectiveness.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Effectively prevents double feeds during the conveyance of thick paper by ensuring only one sheet passes through the gap, thereby maintaining accurate sheet separation and preventing double feeds.
Implementation Method 1
a suction conveyor disposed vertically above the sheets of paper stacked in the stacker for sucking and conveying the sheets of paper
Implementation Method 2
a blower that blows air onto the sheets of paper sucked by the suction conveyor
Data Source
AI summary
A sheet feeding device includes: a stacker that stacks sheets of paper; a suction conveyor disposed vertically above the sheets stacked in the stacker for sucking and conveying the sheets; a blower that blows air onto the sheets; and a regulating member disposed on a downstream side of the suction conveyor in a conveyance direction, facing an outlet of the sheets of the suction conveyor and projecting vertically upward, wherein the suction conveyor includes: horizontal portions provided on both ends in a width direction; and a recess provided in an intermediate portion and recessed vertically above the horizontal portions, and a lower limit of a projection height of the regulating member is set so that, when there is a vertical gap between a vertical upper end portion of the regulating member and the horizontal portions, a length of the gap is less than twice a thickness of the sheets.